Note that module files (.ccm files in the example) cannot be parsed in parallel like that. The build system has to know what order to parse module files in. I g

Note that module files (.ccm files in the example) cannot be parsed in parallel like that. The build system has to know what order to parse module files in. I guess if all .ccm files only did #includes and no imports, the provided Makefile example would work, but that seems like a niche use case. Instead, some sort of dependency graph amongst the .ccm needs to be encoded in the Makefiles. There is an ISO paper describing how to query a compiler for this info (see https://wg21.link/p1689 https://wg21.link/p1689). Other papers sketch out how one might incorporate that into a dynamic Makefile graph, but so far nobody seems interested in going that far. Switching to a more actively maintained build system is probably the interesting alternative. If you want to learn more about how build systems can support C++ modules, see this blog post by the CMake maintainers. The principles translate to most (all?) nontrivial build systems. https://www.kitware.com/import-cmake-c20-modules https://www.kitware.com/import-cmake-c20-modules